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A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron (Cr of 15%) is not high sometimes, but its cost is not low. Thus, medium Cr Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball on ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of medium Cr Si cast iron are superior to those of martensitic high chromium cast iron (Cr of 15%). The main reasons are that (1) the stress in medium Cr Si cast iron is released in the as cast state; (2) the matrix is fine pearlite with better toughness and plasticity; (3) the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; (4) high silicon content improves the morphology of eutectic carbide; (5) there is no secondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear. 相似文献
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Wear parts are greatly consumed in metallurgi-cal industry,fire power stations and cement works.The consumption of grinding balls and lining platesmay be the greatestunder such impactabrasive wearconditions.In China,annual consumption of ballsand plates is close to 1× 10 6 t.Therefore,develop-ing a new material for impact wear conditions is veryimportant. The martensitic high chromium cast iron(WCr= 15 % ) is widely studied and used as wear resis-tance material[1— 8] ,especially for ma… 相似文献
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Effect of RE Modification and Heat Treatment on Impact Fatigue Property of a Wear Resistant White Cast Iron 总被引:5,自引:0,他引:5
Withhigherhardnessandbetterwearresistance ,whitecastironscanbeusedaswearresistantpartsinmanyfields .Inpractice ,thewearresistantpartsareoftenrequiredtobesubjectedtogrindingofabrasivesandrepeatedimpactaction .Therefore ,fatiguecracksareliabletobegeneratedo… 相似文献
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The thermal fatigue behavior of wear resistance cast iron with different quantity of deformation has been investigated. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, approving that the more serious, the carbide breaks. The higher thermal fatigue resistance of wear resistance cast iron will be and thermal fatigue fracture belongs mainly to brittleness. 相似文献
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CHANG Li-min LIU Jian-hua 《钢铁研究学报(英文版)》2006,13(1):36-39
Chromium wear resistant cast iron is widelyusedin engineering, mining and power industry forits high strength,hardness and wear resistance .Inproduction process , some wear-resistant parts ser-ving in alternative stress due to rapid heating andcooling rate ofteninduces thermal fatigue andresultsinfailure .The badthermal fatigue property of chro-mium wear resistant cast iron is due to eutectic car-bides which distribute as continuous net in matrix.Recent researches showthat hot deformation can … 相似文献
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利用MCF-30型冲蚀磨损试验机对镍铬铸铁进行冲蚀磨损试验,采用扫描电镜(SEM)、透射电镜(TEM)、XRD技术对其组织和冲蚀磨损后的形貌进行表征,分析了冲蚀角、冲蚀介质酸碱度对其冲蚀磨损性能的影响,总结了其冲蚀磨损规律。结果表明,镍铬铸铁在960℃风淬+250℃回火处理后,Cr与Fe、C形成(Fe,Cr)3C型合金碳化物,呈断续网状分布,起到了抗磨骨架的作用,Ni固溶于铁素体中强化基体;不同冲蚀角下,其冲蚀磨损曲线呈现"M"形,最大冲蚀率出现在60°冲蚀角;强酸对其冲蚀磨损影响较大,当pH≥3的时候,弱酸对其冲蚀磨损量几乎无影响。对其冲蚀磨损机理进行了分析。 相似文献
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研究了不同硼含量对含碳3.4%-3.8%、含硅2.0%-3.0%,含锰2.0%-=3.0%的球墨铸铁铸主热处理态组织和力学性能的影响。结果表明:随着硼含量的增加,铸态组织中的碳化物数量增加,硬度提高,冲击韧性下降,当硼含量大于0.010%时,铸态组织中出现了明显的网状或断网状碳化物,冲击韧性下降幅度较大,经淬火、回火后、碳化物发生不同程度的溶解。当硼含量为0.003%-0.0105时,热处理后碳化物基本消失,硬度保持在HRC50左右,冲击韧性达到或超过9J/cm^2;当硼含量超过0.010%时,热处理后仍存在断网状或条块状碳化物,硬度稍有增加,冲击初性明显下降。 相似文献
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Wear behavior and mechanism of spheroidal graphite cast iron were studied on a pin-on-disk elevated temperature wear tester. The phase and morphology of worn surfaces were examined by X-ray diffraction and scanning electron microscopy. Results show that with an increase of load, wear rate of spheroidal graphite cast iron gradually increases under low loads, rapidly increases or potentially increases under high loads; wear rate increases with increasing ambient temperature. At 25–200 °C, adhesive wear prevails; oxidative wear and adhesive wear coexist at 100 °C. As load surpasses 150 N at 100 °C, extrusive wear appears. The elevated-temperature wear of spheroidal graphite cast iron is a physical and chemical process including the following reactions: xFe + y/2O2?FexOy, 2C + O2?2CO and FexOy + yCO?xFe+yCO2. Hence, at 400 °C, the amount of graphite and tribo-oxides are substantially reduced because of reductive function of graphite. It can be suggested that wear-reduced effect of graphite and tribo-oxides is impaired. 相似文献
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EffectofREComplexInoculationontheFatigueWearBehavioursofHighChromiumCastIronWangJiubin(InstituteofIron&SteelResearch,AnshanIr... 相似文献
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用透射电子显微镜和扫描电镜研究了铸铁中开花状石墨的微观结构,结果表明,开花状石墨是石墨沿[0001]方向生长速率增大的过程。因而它是1种过球化石墨,而不是铸铁过程中球化不良造成的。 相似文献
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研究了残余奥体对中锰白口铸铁力学性能和抗磨性的影响,结果表明,冰冷处理是改变显微组织中残余奥氏体量和马氏体量的可靠工艺。随显微组织中残余奥氏体量的减少,材料的硬度提高、冲击韧性降低。残余奥氏体含量为30%时,模拟试验的抗磨性最好,用于制造中小型球磨机衬板的中锰白口铸铁,合适的残余奥氏体含量为30%-35%,此时可以达到硬度、韧性和抗磨性的最佳配合。 相似文献
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The microstructure of graphite spherulites (G.S.) in Ce addition ductile cast iron was carried out using transmission electron microscopy (TEM) techniques. The structral characterization of the graphites is as following: there are platelets growing along the periphery as well as fan-like structure formed from platelet aggregates in the diameter section of spherulite, in which most of the platelets are with sizes ranging from several to tens nm in radial; the [001] direction of the platelets would have a tend to parallel to radial of the G. S. and meanwhile, they also a small misorientation deviated from the radial among the platelets each other. It shows that the anisotropy of graphites has been restrained by adding Ce element in cast iron and the structural characterization of the G. S. is consistent with the Double’ s model of the conical helixes formed in helical growing and branching. 相似文献
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Sinan Korkmaz 《钢铁研究学报(英文版)》2011,18(8):42-45
Mechanical, physical and manufacturing properties of cast iron make it attractive for many fields of application, such as cranks and cylinder holds. As in design of all metals, fatigue life prediction is an intrinsic part of the design process of structural sections that are made of cast iron. A methodology to predict high-cycle fatigue life of cast iron is proposed. Stress amplitude-strain amplitude, strain amplitude-number of loading cycles relationships of cast iron are investigated. Also, fatigue life prediction in terms of Smith, Watson and Topper parameter is carried out using the proposed method. Results indicate that the analytical outcomes of the proposed methodology are in good accordance with the experimental data for the two studied types of cast iron: EN-GJS-400 and EN-GJS-600. 相似文献
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合金球墨铸铁基体组织对含镍球墨铸铁热疲劳性能的影响 总被引:4,自引:1,他引:4
将同炉熔炼并同时浇铸的 ,镍约 0 .7%的合金球墨铸铁楔形试块粗加工后热处理成 6种基体组织 ,再精加工成 2 0 m m× 2 0 m m圆柱试样。对试样进行了 (6 0 0± 10 )℃ (盐浴 )~ (70± 30 )℃(油 )和 (6 5 0± 10 )℃ (盐浴 )~ (2 5± 5 )℃ (水 )两种冷热循环试验 ,得到了一致的结果。发现 ,不同基体的试样其抗热疲劳性能由高到低依次为 :下贝氏体基体→ 5 6 0℃回火调质基体→ 5 80℃回火调质基体→ 6 0 0℃回火调质基体→正火片状珠光体基体→奥 -贝基体。作者结合不同基体组织的硬度和强度以及 Ac1 点以下温度范围内上述各种基体组织的热力学稳定性等因素对热疲劳性能的影响 ,阐明了导致上述试验结果的原因。 相似文献
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EffectofRareEarthElementsonThermalFatigueofHighNi-CrAlloyCastIronYangQingxiang(杨庆祥);WangAirong(王爱荣);RenXuejun(任学军);WuHaoquan(... 相似文献
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